Dong-Sik Shin

Molecular theranostics, integrating precise diagnosis with targeted therapy, represents a cornerstone of personalized medicine. As a pivotal metabolic cofactor, reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) is intrinsically linked to cancer progression and survival when dysregulated. In this study, we report DE‐CQ , an NAD(P)H‐activatable fluorophore that enables both cancer imaging and apoptosis. DE‐CQ allows the real‐time quantification and visualization of intracellular NAD(P)H, serving as a robust molecular indicator of cancer malignancy. Beyond its diagnostic utility, DE‐CQ preferentially induces mitochondria‐ and ER stress‐dependent, caspase‐mediated apoptosis in aggressive MDA‐MB‐231 cancer cells while maintaining minimal toxicity toward normal cells. Our findings demonstrate that DE‐CQ functions as a potent theranostic agent, simultaneously providing diagnostic insights into cancer aggressiveness and triggering cell death. Given its dual functionality and high selectivity, DE‐CQ holds significant potential as a next‐generation platform for advanced, personalized cancer treatment.

Molecular theranostics, integrating precise diagnosis with targeted therapy, represents a cornerstone of personalized medicine. As a pivotal metabolic cofactor, reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) is intrinsically linked to cancer progression and survival when dysregulated. In this study, we report DE‐CQ , an NAD(P)H‐activatable fluorophore that enables both cancer imaging and apoptosis. DE‐CQ allows the real‐time quantification and visualization of intracellular NAD(P)H, serving as a robust molecular indicator of cancer malignancy. Beyond its diagnostic utility, DE‐CQ preferentially induces mitochondria‐ and ER stress‐dependent, caspase‐mediated apoptosis in aggressive MDA‐MB‐231 cancer cells while maintaining minimal toxicity toward normal cells. Our findings demonstrate that DE‐CQ functions as a potent theranostic agent, simultaneously providing diagnostic insights into cancer aggressiveness and triggering cell death. Given its dual functionality and high selectivity, DE‐CQ holds significant potential as a next‐generation platform for advanced, personalized cancer treatment.

An adhesive conductive hydrogel (ACH) is developed based on a polyacrylamide–poly(ethylene glycol) diacrylate (AAm@PEGDA) matrix functionalized with polydopamine (PDA) and poly(3,4‐ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS), aiming for application as a flexible electronic bio‐interface (EBI). ACH features a porous structure with a swelling ratio of approximately 300% in artificial sweat and maintains breathability approximately 2.5 times longer than conventional PEDOT:PSS‐based conductive hydrogels (CHs). It exhibits tunable mechanical properties (2.5–10 MPa), excellent elasticity, and strong skin adhesion (~1 mN). Electrical conductivity is significantly enhanced through post‐treatment in deionized water, reaching 3.66 × 10 ⁻⁵ S/m—about 345 times higher than the commercial adhesive conductive hydrogel sample. This aqueous treatment provides a more biocompatible alternative to organic solvents such as dimethyl sulfoxide. Surface electromyography (sEMG) measurements demonstrate a signal amplitude of 0.2836 V and a signal‐to‐noise ratio (SNR) of 12.46 dB, showing comparable performance to PEDOT:PSS hydrogels (11.4 dB) despite the incorporation of PDA for enhanced adhesion. The ACH shows no cytotoxicity or sensitization responses in biological evaluations. Its high moisture retention supports ionic transport during long‐term wear and offers potential for sweat‐based biomarker sensing. These properties suggest ACH is well‐suited for use as an EBI and holds strong potential for next‐generation wearable electronics and sEMG monitoring applications.

Matrix metalloproteinase‐9 (MMP‐9) plays a key role in extracellular matrix remodeling and is implicated in various physiological and pathological processes, including tissue regeneration and cancer progression. Accurate quantification of MMP‐9 is essential for diagnostic and therapeutic applications. In this study, we developed a protease‐based fluorescence enzyme‐linked immunosorbent assay (ELISA) platform utilizing biotinylated α‐chymotrypsin (α‐CTB) as an alternative enzymatic reporter to conventional horseradish peroxidase (HRP). α‐CT was conjugated with biotin using biotinamidohexanoic acid 3‐sulfo‐N‐hydroxysuccinimide ester, achieving a labeling ratio of approximately 6.5:1 without significantly compromising enzymatic activity. The biotinylation efficiency was verified using the 2‐(4‐hydroxyphenylazo)benzoic acid (HABA)–avidin assay, and proteolytic activity was assessed with the fluorogenic substrate. Comparative kinetic analysis revealed that α‐CTB retained substantial activity, including when immobilized on streptavidin‐coated surfaces, validating its use in solid‐phase immunoassays. The α‐CTB‐based ELISA was applied to quantify MMP‐9 and compared with a conventional HRP‐based ELISA. The α‐CTB assay exhibited a concentration‐dependent increase in fluorescence across a broad dynamic range, achieving a lower limit of quantification (LOQ) of 1.49 ng/mL, whereas the traditional ELISA showed reduced sensitivity at low concentrations with an LOQ of 3.19 ng/mL. This improved sensitivity demonstrates the suitability of α‐CTB as an alternative enzymatic reporter for accurate biomarker quantification.